HW15 - Chemistry Unit 1 Recap PDF

HW15 – Unit 1 Recap Name: Chemistry, Period _____ Date: 1 nm = 1.00 x 10-9 m, c = 3.00 x 108 m/s, h = 6.626 x 10-34 J∙s 𝐡𝐜 E = hν...

HW15 – Unit 1 Recap Name: Chemistry, Period _____ Date: 1 nm = 1.00 x 10-9 m, c = 3.00 x 108 m/s, h = 6.626 x 10-34 J∙s 𝐡𝐜 E = hν E= c = λν 𝛌 1. What is the frequency of radiation if its wavelength is 5.80 x 10-7 m? a. The value of λ = b. The unknown (what you are solving for) is. c. The symbol for the unknown is. d. The equation you will use to solve problem is. e. Any constant you will use, what is it? f. The value of the constant e. Solve the problem (show step by step). 2. What is the energy of light if its wavelength is 4.25 x 10-7 m? a. The value of λ = b. The unknown (what you are solving for) is. c. The symbol for the unknown is. d. The equation you will use to solve problem is. e. Any constants you will use, what are they: (a) (b) f. What are the values for the constants: (a) (b) e. Solve the problem (show step by step). 3. What is the frequency of light if its energy is 4.25 x 10-19 J? a. The value of energy = and the symbol for energy = b. The unknown (what you are solving for) is. c. The symbol for the unknown is. d. The equation you will use to solve problem is. e. Any constant values you will use, what are they: (a) e. Solve the problem (show step by step). 4. If the energy of light is 6.15 x 10-19 J, what would be the wavelength of this light? 5. Draw an absorption energy level diagram for an electron at the ground state level of n = 2 and transitions to n = 5. Label the parts of the diagram (energy axis, ground state, excited state, light coming in, electron transition) 6. Draw an emission energy level diagram for an electron at an excited state level of n = 4 and transitions to n = 1. Label the parts of the diagram (energy axis, ground state, excited state, light coming out, electron transition) 7. Draw a Bohr diagram for sulfur, S. Include electrons in diagram. a. # electrons are in sulfur b. # of energy levels c. # valence electrons d. Energy level where valence electrons can be found 8. Draw the following orbitals. Make sure to label the axes. a) pz b) dz2 c) dxy 9. If n = 3, what are the possible values of l? 10. If l = 2, what are the possible values of ml ? 11. Draw an energy level diagram that include the orbitals, 1s, 2s, 2p, 3s, 3p, 3d, 4s, and 4p. Then fill the orbitals with electrons (arrows) corresponding to the element chromium. (Hint: start with the lowest energy) 12. Write the electron configuration and the orbital diagrams for the following elements. a) Carbon, C b) O c) sodium, Na d) phosphorus, P e) titanium f) arsenic, As 13. Determine the number of valence electrons for the following elements a) Mg b) Cl c) Si d) K 14. Circle the ions that are isoelectronic with argon, Ar. Br Cl Cl- K K+ Ca2+ S2- 15. For each pair, circle the element or ion that has a larger radius. a) Mg or Al b) O or Se c) Li or F 16. The Table shows the atomic radii of some period 3 elements from the Periodic Table. Element Symbol Atomic Number Atomic Radii (pm) Na 11 190 Mg 12 145 Al 13 118 Si 14 111 P 15 98 S 16 88 Cl 17 79 The decrease in the atomic radii of the elements in this table can best be explained by: A. As the number of protons increases, the attraction between the positive nucleus and the negative electron cloud decreases, thus pulling the electrons toward the nucleus and increasing the radii. B. As the number of protons increases, the attraction between the positive nucleus and the negative electron cloud increases, thus pulling the electrons toward the nucleus and decreasing the radii. C. As the number of protons increases, the new protons are added in outer shells which decreases the pull of the positive nucleus to the negative electron cloud, thus decreasing the radii. D. As the number of protons increases, the new protons are added in outer shells which decreases the pull of the positive nucleus to the negative electron cloud, thus increasing the radii. 17. Sulfur is in group 4B of the Periodic Table and normally holds 4 valence electrons before it reacts with other elements. Which of the following electron configurations matches sulfur? a) 1s22s22p63s23p3 b) 1s22s22p63s23p4 c) 1s22s22p63s23p5 d) 1s22s22p63s23p6 18. Calcium has an electron configuration of 1s22s22p63s23p64s2. Based on this information, how many valence electrons does calcium have? a. 2 b. 4 c. 6 d. 8 19. Why do atoms get smaller as they move left to right in a period? due to increase nuclear charge and no added shielding 20. Which element in in each pair has a larger ionization energy? a) Na or O b) I or Ne c) Ca or Fr 21. What is ionization energy? What is first ionization energy (IE1)? 22. What is the periodic trend for first ionization energy? IE increases going from left to right due increased nuclear charge, and decreases down a group due to increased distance of valence electrons from the nucleus and increased shielding by the inner shell electrons. 23. Arrange the following group of elements in order of increasing ionization energy a) Be, Me, Sr b) Bi, Cs, Ba 24. As each successive element in Group 5 (15) of the periodic table is considered in order of increasing atomic number, the atomic radius _________. a) decreases b) increases c) remains the same 25. The strength of an atom’s attraction for the electrons in a chemical bond is the atom’s a) electronegativity b) ionization energy c) heat of reaction d) heat of formation 26. Which properties are most common in nonmetals? a) low ionization energy and low electronegativity b) low ionization energy and high electronegativity c) high ionization energy and low electronegativity d) high ionization energy and high electronegativity 27. Which Group 7 (17) element has the least attraction for electrons? a) F b) Cl c) Br d) I 28. As the elements of Group 1 on the Periodic Table are considered in order of increasing atomic radius, the ionization energy of each successive element generally _______. a) decreases b) increases c) remains the same 28. Compared to the atomic radius of a sodium atom, the atomic radius of a magnesium atom is smaller. The smaller radius is primarily the result of the magnesium atom having __________. a) a larger nuclear charge b) a smaller nuclear charge c) more principal energy levels d) fewer principal energy levels 29. Which of these elements has the least attraction for electrons in a chemical bond? a) oxygen b) nitrogen c) fluorine d) bromine 30. The ability of carbon to attract electrons is. a) greater than that of nitrogen, but less than that of oxygen b) less than that of nitrogen, but greater than that of oxygen c) greater than that of nitrogen and oxygen d) less than that of nitrogen and oxygen